Enhanced single-electron transfer for efficiently photocatalytic H2O2 production over g-C3N4 decorated with TEMPO-oxidized cellulosic carbon

Abstract

Designing efficient semiconductors for photocatalytic oxygen reduction reaction (ORR) without sacrificial agent is an urgent challenge for H2O2 production under ambient condition. Graphite carbon nitride (g-C3N4) exhibits controllable regulation in band structure and light absorption for photocatalytic process. However, the photocatalytic H2O2 synthesis by pristine g-C3N4 is poor due to the fast recombination of photogenerated carriers and unfavorable selectivity of ORR. To enhance the photocatalytic H2O2 production, different types of carbon can use in combination with g-C3N4. In the present work, we show how cellulose fiber from bamboo can lead to hybrid C/ g-C3N4 photocatalyst with enhanced photocatalytic activity and H2O2 production rate of 121.75 μmol·L−1·h−1, which is 6.2-fold higher than that of pure g-C3N4 without any sacrificial agent. The experimental results confirmed that TEMPO-cellulose derived hydrophilic carbon can not only accelerate the transfer of photo-generated electrons as well as efficient charge carrier separation, but also promote the sequential two-step single-electron ORR route. Thus, this work provides a pioneering perspective for tuning the electronic interaction between g-C3N4 and cellulosic carbon for enhanced photocatalytic H2O2 synthesis.